Telephone-exchange apparatus



(No Model.) hem-sheet 1.

0.. E. BUELL-r TELEPHONE EXCHANGE APPARATUS.

No. 248,138, Patented Oct. 11,1881.

(No Model.)

. 2 Sheets-Sheet '2. O. E. BU ELL.

TELEPHONE EXCHANGE-APPARATUS.

No. 248,138. men d Oct. 11,1881.

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WITNESSES:

MOM BEN-(0L N PETERS. Phulu-Lilhumpher. Wnxhmgmm D, C.

UNITED STATES PATE T OFFICE.

CHARLES E. vBUELL, OF NE'VV HAVEN, CONNECTICUT, ASSIGNOR OF TWO- THIRDSTO JAMES SMITH, OE HACKENSACK, NEW JERSEY, AND GEORGE W. COY, OFMILFORD, CONNECTICUT.

TELEPHONE-EXCHANGE APPARATUS.

SPECIFICATION forming part of Letters Patent No. 248,138, dated October11, 1881.

I Application filed June 15, 1881. No model.)

new and useful Improvements in Telephone- Exchange Apparatus, of whichthe following is a specification.

My invention constitutes an improvement upon that class oftelephone-exchange apparatus in which the connection and disconnectionof the subscribers lines with one another are effected from thesubscribers stations and. without the assistance of ceutral-officeattendants.

Although I have shown in theaccompanyin g drawings one particular formof automatic switch for the purpose of illustration, my invention isapplicable to any automatic exchange apparatus.

As hitherto constructed, automatic switch apparatus has been defectivein that it has been impossible for direct communication to be held,telephonically or otherwise, between the central office and subscribersover the wires used in operating the switch and in communicating betweensubscribers,while,fu rth er, in case of accident to the switch orderangement thereof, the business of the exchange would for the timebeing come to a stand-still.

The objectof my invention is to remedy these defects and to providemeans whereby, without disturbing the automatic switch, oralcommunication may be held between the central office and any subscriber,or vice versa, while, further, in case of derangement of any portionv orall of the automatic switch devices, communication may still be heldbetween subscribers.

To this end my invention consists in interposing between the automaticswitch and the subscribers lines a manually-operated telephone-exchangeswitch of any ordinary construction, the various subscribers circuitspassing through said switch to the automatic switch, means being alsoprovided for connecting the various lines to ground before passing .tothe automatic switch and for disconnecting or breaking the connection toground through the latter. 0

I have shown in the accompanying drawings, Figures 1 and 2, two forms ofmanually-operated switch and two ways of carrying out my invention.Other switch-hoards and other means or devices for making the variouselect-rical connections contemplated by me may,

7 however, be substituted for those shownwithout departing from thespirit of theinvention. Referring to Fig. l of the-drawings, A represents a section of an automatic switch constructed after the mannerset forth in Letters Patent of the United States granted M. D. and TA.Connolly and T. J. McTighe,December 9, 1879, No. 222,458, beforereferred to, wire 6 of the subscribers wires beingshown as connectedthereto. I

The various subscribers circuits are numbered from 1 to 6,consecutively, and each passes to the automatic switch and itsearth-connections through a manually-operated telephone 7 switch-board,C, interposed between the auto matic switch A and the various lines.Entering the central office, each circuit is, through an annunciator andcall-bell, a,;to a key on switch, I), adapted to disconnect the linefrom the switch-board and" connect it to a calling battery or generator,0,- to a spring-jack, d, of any approvedconstruction, to he used in con-,nection with divided insulated metallic tips 6 6, connected totelephone communicating apparatusM; to avertical strip, e,of theswitchboard; to a switch,f, and thence to the controlling devices of theautomatic switch, and to earth. Line6 is shown connected to asubscribers station atB, at which point the appa- 5 .ratus is ofsubstantially the construction indicated in the patent to Connolly andMcTighe;

S representing the switch adapted to connect the line either to arheotome, B, and a polechanger, O, for battery P, to a call-bell, R, or9 to a telephone, T. Said switch also closes the circuit of battery 1?through the electrodes and the primary of the induction-coil in M T atthe same time that it connects the line to the telephone-receiver T. 5

The switches f in switch apparatus C are each adapted to break thecircuit of a subscribers line with the automatic switch apparatus andits ground and connectthe line to earth through a wire, 9.

The normal operation of the system when the various subscribers circuitspass to the switch apparatus A is the same as the patent above referredto, and need not be rehearsed. Should, however, oral communication bedesired between the central oflice and a subscriber, or vice versa, theswitch-board apparatus 0 may be instantly brought into use, thepredetermined signal necessary to make such a desire on the part of asubscriber known being given on the bell a by the opening and closing ofthe battery P by means of switch S or other device, while, vice versa,the central-ctfice-attendant depresses hey I), thus placing battery orgenerator 0 to line and simultaneously disconnecting the line from theautomatic and the manual switch devices, so as to prevent thebattery cfrom affecting the electromagnetic devices of switch A.

Telephoneapparatus M may beinserted into the line by means of thespring-jacks d and tips 6. The necessity for such communication mayarise from a failure of the automatic switch device to operate properly,so as to place a subscriber in communication with the party desired, inwhich case he can communicate to the central-office attendant the factthat he fails to get a response, and the attendant thereupon makes thedesired connection in switch-board C, before doing which he disconnectsthe switchesffrom the points to which are connected the wires leading tothe automatic switch A.

Should the automatic switch become so far deranged as to require repairand make its further use for the time being impossible, it and itsearth-connections may be entirely disconnected from the subscriberswires by means of the switches f, and the ground-connection gsubstituted. The lines may then be connected and the business of theexchange continued without interruption by means of the switch 0 alone,its operation in this duty being well understood. Other contingenciesmay arise under which it may be brought either wholly or partially intouse in conjunction with or wholly independent of switch A; but I do notdeem it necessary to specify them all.

In Fig. 2 of drawings I have shown a somewhat different form of manualswitch-board, although the general operation of the apparatus issubstantially the same as that of Fig. 1. Instead of the switches fnormally interposed in the circuit and adapted to be turned, so as tosubstitute a ground-connection, g, I employ an upper row of switches, t,whose pivots are connected to ground 9, and a series of connectingplugs,at. one in each circuit.

Switches t may be turned so as to connect with the line-strips e, thusconnecting the lines to ground, while the connection of the variouscircuits with the automatic switch A is controlled by the plug-switchesX.

Instead of connecting-strips m, as shown in Fig. 1, switch-levers n areused for connecting the lines. The operation ofthese devices is wellunderstood.

In Fig. 2, line 1 is shown connected to the subscribers station B and tothe automatic switch A. Another form of pole-changer, G, is here shown.The effect of turning its arm 11 12 so as to occupy the position shownin full and dotted lines and connect with the segments H can be readilyfollowed by tracing the circuits. The switch S connects the line torheotome, bell, and telephone in the manner indicated, (also shown inFig. 1;) but the circuit of the battery through the transmitter iscontrolled by a gravity-switch, G S, in a wellknown manner.

Other forms of manual central-oflice switch may be substituted for thoseshown by interposingthem in the circuits in substantially the samemanner.

What I claim as my invention is- 1. The combination, with an automatictelephone-exchange switch, of a manual exchangeswitch interposed in thesubscribers circuits between the lines and the automatic switch,substantially as described.

2. The combination of an automatic telephone-switch, a manualexchange-switch interposed in the subscribers circuits between the linesand the automatic switch, and devices adapted to break the connection ofthe lines with the automatic switch and to substitute an independentground-connection for the manual switch.

3. The combination, substantially as described, of an automatictelephone-exchange switch and a manual exchange-switch interposedbetween the automatic switch and the lines, and signaling-keys adaptedto make connection with a generator and to simultaneously breakconnection with the automatic switch devices, substantially asdescribed.

4. The combination, substantially as described, of an automatictelephone-exchange switch, a manual exchange-switch, and adisconnecting-switch interposed between the two and adapted to close anindependent connection to earth.

CHARLES E. BUELL.

\Vitnesses:

J 0s. R. EDsoN, GEORGE W. 001*.

IIO

